Container



March 22, 1966 J. H. LOVE ETAL CONTAINER 2 Sheets-Sheet l Filed Aug. 19, 1963 /Nl/ENTORS JAMES H- LOVE ATTORNE V March 22, 1966 J. H. LOVE ETAL CONTAINER 2 Sheets-Sheet 2 Filed Aug. 19, 1965 a, wwwwk/ Wh ,www W .i L \w/ /m l HON k l@ ,w l Y I MM MVN m New?- ,W2 N QI i QMQWLMIQH -Ww @mmm mm Q m, x

JA M55 H. L o VE VEN @gi L /ONEL w01. PERT 3 mbLo--/V QM ATTORNEV United States Patent O 3,241,705 CONTAINER .llames H. Love, Summit, and Lionel Wolpert, Fords, NJ., assignors to Air Reduction Company, Incorporated, New York, N.Y., a corporation of New York Filed Aug. 19, 1963, Ser. No. 303,053 3 Claims. (Cl. 220-14) This invention relates to containers or tanks or vessels for materials as low or high temperature fiuids.

This invention is more particularly concerned with double-Walled insulated containers adapted for storing and/ or dispensing and/ or transporting liquefied gases.

Many designs, apparatus, and systems have been proposed and utilized for double-walled insulated containers or receptables for fluids of temperatures widely divergent from atmospheric temperature, such as for low temperature fluids. These containers are also termed liquefied gas tanks, liquefied gas containers, liquid vessels, vacuum tanks, vacuum asks, and dewar vessels. In general these containers consist of an outer vessel surrounding and spaced from an inner vessel. The inner vessel inside the outer vessel is separated from the outer vessel by insulation. The inner vessel contains the lower temperature uid as a liquefied gas and gas vapor. Associated with the container are means for introduction of fluid into the inner vessel and withdrawal of gas or vapor or liquid from the inner vessel when required. These containers have been designed or proposed with regard to solving problems of heat fiow to the low temperature material in the inner vessel; problems of supporting the inner vessel in relation to the outer vessel; problems of insulating the space or area between the inner and outer vessel; problems of product delivery from the inner vessel; and other problems. Many of these prior art systems have merit, but in many cases complex support structures are proposed and utilized, and many of these systems result in difficult and complex fabrication techniques being required. Further, multiple layer insulation or laminated insulation materials and techniques are not easily adapted to many of these systems and procedures. In many cases the containers will be utilized with bulk carriers or transportation vehicles and vessels or as semi-trailers or tank mounted trucks in transporting liquefied gas. For example, trucks and railroad cars carrying perishable materials use low temperature liquefied gases, as liquid nitrogen to maintain the perishables in a refrigerated state. That is liquid nitrogen may be fed directly to area or space of the vehicle containing the perishable materials. Under these conditions of use the containers are subject not only to the normal static loadings, but the containers are also subject to severe and high dynamic loadings, because of the movement and Stopping of the vehicles. It therefore becomes a problem to provide satisfactory containers with regard to heat leak properties, loading support and product withdrawal, while providing a simplified container structure. Additionally it is desirable to provide a container where the product, as liquid nitrogen, is fed by gravity flow with the preferred aid of a pressurizing coil to the area of utilization; and to provide a container that can be substantially emptied by gravity-product flow. Prior art containers utilizing coiled product withdrawal lines, or similar systems, have product fiow paths and a higher pressure drop that do not allow satisfactory and complete product withdrawal from the container by gravity In summary, prior art systems do not product tiow. solve all of the problems of providing containers that are satisfactory with regard to simplified construction, heat leakage, dynamic loadings, support structures, and complete product withdrawal by gravity fiow.

It is, therefore, an object of this invention to provide improved containers or tanks or vessels and improved systems for the storage, handling, dispensing, and transportation of low temperature materials.

Another object is to provide improved, advantageous, and simplified double-walled containers for liquefied gases.

A further object is to provide improved designs, systems and procedures relating to fabricating and assembling double-walled containers.

A still further object is to provide improved product feed and product withdrawal systems and support systems for liquefied gas vessels or containers and allowing the container to be emptied by gravity product flow.

Another object is to provide support systems for inner Vessels in containers.

A further object is to provide containers that have improved static and dynamic load characteristics.

Another object is to provide containers having long heat flow lines to the inner vessel and containers utilizing improved insulation techniques.

These and other objects, as well as other advantages and benefits of the invention, and other novel and specific features and details of the invention will become apparent, and will be clarified, and will be more specifically detailed and described in the following descriptions, details and illustrations, examples, and in connection with the accompanying drawings in which like references, characters, and symbols refer to similar structures, members, parts, apparatus, or materials throughout the several views, and in which:

FIGURE l is a generalized longitudinal sectional view of a container showing details of the invention, taken along line 4 4 of FIGURE 2;

FIGURE 2 is a schematic cross-sectional view taken somewhat along line 3-3 of FIGURE 1 and illustrative of the radial support system of containers of the invention;

FIGURE 3 is a sectional View similar to FIGURE 1 illustrating a modified form of the invention;

FIGURE 4 is a schematic cross-sectional View taken somewhat along line 7 7 of FIGURE 3, similar to FIGURE 2, illustrating the modified form of the invention shown in FIGURE 3.

FIGURE 5 is similar to FIGURE l, illustrating modifications of the invention.

In accordance with the invention improved doublewalled containers are constructed or fabricated with hollow members or recesses and fiuid flow lines or conduits associated with the inner vessel of the container whereby the fiuid flow lines are part of an improved support system. The improved containers also include an additional support system on the ends of the inner vessel; the support systems do not interfere with the use of multiple layer insulation around the outer wall surface of the inner vessel. Containers incorporating the features of the invention have improved properties with regard to product withdrawal by gravity, heat leak or heat flow characteristics, simplification of fabrication, simplification of utilizing of multiple layer insulation, and support systems for severe dynamic loadings.

Shown in FIGURES l to 5 are generalized sectional Views of containers of this invention. The container or receptacle is identified generally by the reference numeral 20. FIGURE 1 is a sectional View along the longitudinal axis of container 20. The container 20 consists mainly of two generally cylindrical longitudinally extending vessels 21, 22, with support systems, fiuid lines, and insulation. The vessels 21, 22 may be spherical in shape. The outer vessel 21 or outer container 21 surrounds the inner vessel 22, to provide a double-walled construction, and is spaced from the inner Vessel 22 to provide an intervening chamber for utilization of vacuum insulation techniques, support systems, and liuid liow lines. Both vessels 21, 22, have the same general shape and are spaced so that they have a common longitudinal axis. The inner vessel 22 or inner container 22 has a front end wall 23 and a rear end wall 24 and a generally cylindrical side wall 25, as shown. The ends of the inner and/ or outer vessel may be formed as a surface of revolution, as shown in FIG- URE 3. That portion of the intervening chamber, of generally annular shape, between the side wall 25 and vessel 21 is free of any obstructions, as support system members, fluid lines or fittings. By having this space free from obstructions, one can readily use laminated or multiple layer insulation in this space without any difficulties in fabrication or application of the insulating material. That is uniform and continuous space portions are desirable when multiple layer insulation techniques are used. By providing this unobstructed space portion of generally continuous annular shape with multiple layer insulation 26, one reduces the total amount of the intervening chamber required for insulation purposes, with the result that the size of vessel 21 may be decreased or the size of vessel 22 may be increased. The remaining space portions of the intervening chamber between the front end wall 27 of vessel 21 and wall 23, and between the rear end wall 28 and wall 24 are advantageously utilized; for example, for support members, fiow lines, ttings, getter materials, and vacuum fittings. These space .portions may be filled with the convention-al insulation materials 29 (powder, for example). Multiple layer insulation may be used instead of conventional powder insulation in the space portions, if desired. As can be seen from the drawings and the above discussion, insulation of the remaining space portions with multiple layer insulation instead of with conventional powder insulation is more difiicult. The container includes a radial support system and an axial support system. The radial support system consists of rods 30, 31, 32, 33, 34, 35, and support blocks 36 and 37. Other systems for radial support may be substituted for the rods and blocks without departing from the scope of this invention. The axial support system consists of recesses or hollow members 38, 39 and conduits or iiuid flow lines 40, 41. The radial support system supports radial loads applied through the blocks 36, 37. Severe dynamic axial loads encountered because of container 20 movement are supported by the axial support system. The rods 30, 31, 32, 33, 34, 35, and blocks 36, 37 should be as thin as possible to reduce heat iiow or heat leakage. The rods may be made of stainless steel, 9 percent nickel steel, aluminum, copper, nonmetal straps such as nylon or Daeron, or other materials satisfactory for low temperature use. The specific rod diameters are a matter of design dependent on factors such as size, shape, and weight of the inner and outer vessels and the stresses to which they are subjected. Support blocks 36, 37 are joined to the center of walls 23, 24, respectively. The rods are attached to the support block and to the vessel 21. The rods may be offset from a line perpendicular to the longitudinal axis of vessel 22, or can be on a line perpendicular to said axis. As shown in FIGURE 2 the rods 30, 31, 32, are uniformly spaced, 120 degrees apart. Similar spacing is used for the rods 33, 34, 35 on the end wall 24. With regard to the rods 30, 31, 32, they must be positioned so that they do not contact fiow members 40, 41 when container 20l is stationary or moving. In some cases only rod members 30, 31, and 33, 34 are required as shown in FIGURE 3. In this case the rods should be offset about 45 degrees from the vertical line 7-7, as shown in FIGURE 4. Similar spacing should be used for the rods 33, 34 in this modification. The number of rods employed may be varied according to the radial loads anticipated in use. The rod material may be chosen from the rod materials listed earlier in this paragraph. Heat transfer is inversely proportioned to rod length and directly proportional to diameter. Hence, longer thinner rods are desired. The length is limited, however, by the diameter and the length of the outer vessel. The length of the rods used in this invention may be increased within the confines of the vessel by altering the shape of the rods. The axial support system includes the structural portions or hollow members 38, 39, 40, 41. Ex tending from the front end wall 23 and into the interior of vessel 22 are the structural portions or recesses or hollow members 38, 39. All of the hollow members can be conveniently made from tubular or pipe type materials. The hollow members 38, 39 are part of or, are joined or attached to the wall 23 and may also join or attach to the interior wall of vessel 22 for stability in buckling. Support blocks 42 or struts 42 joined to hollow members 38 or 39 and the wall 25 are illustrative of one way to join the member 38, 39 and wall 25. Any convenient method of joining or fabrication may be used. (In smaller containers the joining of members 38, 39 to the interior wall is not required.) All joints are tiuid tight so that no fluids can pass through the interior of members 38, 39 from or to the interior of vessel 22. Also joints involving the vessel 22 should be fiuid tight to prevent fluids from passing from the interior of vessel 22 to the intervening chamber. Preferably support block structure utilized should be of the same material as the inner vessel.

Hollow conduit 40 passes through and is joined to end wall 27, then passes through the intervening chamber, then passes through the interior of member 38, and then into the interior of vessel 22. Conduit 40 is joined or attached to member 38 near the end of member 38. A similar construction is used for the member 39 and conduit 41. The interiors or hollow portions of conduits 40, 41 allow fiuid communication between the interior of vessel 22 and points outside of vessel 21. Conduit 40 is a vent line and allows vapor to be removed from or introduced into vessel 22. Said conduit 40 may be utilized as a top fill line. When top filling, an additional line from the vessel top for use as a vent will be required. Conduit 41 is the product withdrawal line and is also used to introduce liquefied gas into vessel 22. The external portion of the container is adjacent the housing 43. The housing 43 may be utilized for gauges, regulators, valves, and other fittings that may be needed. The auxiliary equipment and fittings associated with conduits 40, 41 are not illustrated. Also product delivery lines to the point of product utilization are not illustrated. As shown in FIGURE l the ends of conduits 40, 41 are bent or fitted with elbows, to place the fluid entrance points of conduits 40, 41 as close to the wall 25 as possible. The end of hollow member 38 or 39 is tapered at the end to join conduit member 40 or 41. Instead of tapering the hollow member a cap or conical member can be joined to the end of member 38 or 39 and joined to conduit member 40 or 41. Conduit members 40, 41 pass through the interior of members 38, 39, respectively and are spaced from the recess walls and do not contact or touch members 38, 39 until the joint area at the end of members 38, 39. By maintaining conduit members 40, 41 spaced from their associated surrounding or encircling members 38, 39, along heat fiow path is provided by the combination tiow lines-support conduits 40, 41. That portion of the interiors of members 38, 39 not occupied by conduits 40, 41 can be filled with insulation material 44 and subjected to vacuum, as in space 29, with which these spaces are in communication. Multiple layer insulation, powder insulation or other known insulation, may also be used. The straight line path without obstructions of hollow members 38, 39 allow for effective multiple layer insulation. The combination of members 38, 41 at the top of end wall 23 and members 39, 41 at the bottom of end wall 23 provides an improved support system for axial loading of vessel 22 and is especially advantageous when the container is subjected to movement. Conduits 40, 41 are substantially straight and have their longitudinal axis parallel to the longitudinal axis of vessel 22. Conduits 4l0, 41 have a low fiud flow resistance and coiling of these flow lines is not required to provide a long heat flow path as the effective points of contact with the vessel 22 are at the ends on members 38, 39 in the interior of vessel 22. By placing the product withdrawal line 4l near the bottom of vessel 22 and eliminating coiling procedures in line 4I, allows the vessel 22 to be substantially emptied of liquid product by gravity iiow through line 41. Ey providing the axial support system at one end wall of vessel 22, slight movements in the position of vessel 22, due to loadings and temperature changes, are possible without changing the basic configuration. That is, this axial support system does not rigidly fix the inner vessel, but still provides for secure mounting of the inner vessel to the outer vessel. Extreme rigidity of attachment could lead to possible fracture of one or more members, or the containers themselves, due to large stresses. Many benefits and advantages result from combining the uid flow members 4t?, 41, with the members 3S, 39; this combination provides an improved fluid system and an improved support system. This support system is especially useful for the severe loadings that are encountered in a direction generally parallel to the longitudinal axis of vessels 2l, 22. The generally straight iiuid flow paths at), 4l provide long heat ow paths without coiling and also form part of the main support system for inner vessel 22.

The containers of this invention comprise generally, two cylindrical vessels. The inner vessel is used to hold a liquefied gas. The outer cylindrical vessel surrounds the inner vessel and is spaced from the inner vessel providing an intervening chamber or intervening area or intervening space that allows insulation of the container. The support structures and fluid lines or piping are assoiated with the ends of the inner vessel with the resulting portion of the intervening chamber around the inner vessel being free of all obstructions. That is, this annular intervening chamber from the front end of the inner vessel to the back end of the inner vessel allows multiple layer insulation to be readily applied to the sides of the inner vessel. Fabrication of the container is therefore simplified and the total amount of the intervening chamber required for insulation purposes is reduced. Further, the distance or spacing between the sides of the inner and outer vessel is reduced or lessened. The inner and outer vessels are hollow cylinders, as shown, and they both consist of two generally circular sections with cylindrical side walls. The ends of both the inner and outer vessels may be surfaces of revolution (as shown, for example, in FIGURE 3) such as ASME liange and dished heads, elliptical heads or hemispherical heads. In most cases the length of the sides measured parallel to the longitudinal axis of the vessel will be greater than the height or radius of the ends of the vessel, measured perpendicular to the longitudinal axis. As indicated these containers are especially useful on over the road, rail and sea transportation of liquefied gases. Any convenient method of mounting the container on the vehicle may be used. Cradle supports, block supports, bracket supports, are useful. For larger vessels the containers may be an integral part of a semi-trailer. When mounted on vehicles, the container should be in a generally horizontal position, that is the liquid surface line in the inner vessel should be generally parallel to the longitudinal axis of the inner vessel. The container may also be mounted in a Vertical position, with product lines acting as tension or compression members in supporting the inner vessel.

The containers of this invention utilize two main support systems. The first support system consists of low heat leak rod members joined to the ends of the inner vessel and the sides of the outer vessel adjacent to the ends of the outer vessel. This support system is provided at both ends of the inner vessel and provides inner vessel support mainly for radial loadings. The second support system is a combination support sys- 6 tem and fluid flow system. This second system provides inner vessel support mainly for axial loadings due to movement of the inner vessel and movement of the liquefied gas in the inner vessel interior. The second system consists of a structural portion or recess extending into the inner vessel and a conduit or fluid flow member attached to the outer vessel and extending into the recess. The second members are in fluid communication with the interior of the inner vessel and pass through the interior of the recess. Generally the recesses or the rst hollow members will be spaced adjacent to the top and bottom of the inner Vessel. The first hollow niembers are sealed or joined to the inner vessel and their associated conduits so that no fluids can pass from the inner vessel to the interior of the first hollow members. The fiuid flow member passes through and is spaced from the first hollow member. The second member may be joined to the first member at any point along the length of the first member. Since it is advantageous to have a long heat leak or heat ow path, the second member should be joined to the first member some distance from the entrance end of the inner vessel. The second member can extend from the entrance end to the other end of the inner vessel. This second support system utilizes a straight second hollow member joined to the outer vessel and effectively joined to the inner vessel by its joint with the first member. Also the hollow members are positioned whereby a long heat flow path is provided by the second member fluid flow lines. Insulation may be used in that portion of the interior of the first hollow member not occupied by the second member.

As indicated the inner and outer vessels of these containers are generally cylindrical, and containers of varying inner vessel capacity are advantageously constructed according to the procedures of this invention.

FIGURE 5 indicates schematically a container 20 associated with a suitable mounting or supporting structure 50, normally, although not limited to two separate saddles, attached to a surface 51 or area Si of a vehicle in which the container is used. Said support structure is shown, for clarity of description, as extending in the same direction as the major axis of the container 20. However, said support structure may extend in other directions, preferably such as a direction perpendicular to said major axis. Reference letters in FIGURE 5 indicate various structural relationships, axes, and dimensions of the various components or structures of the container 20. The reference letter O indicates the length of the outer vessel 2l; N is the length of inner vessel 22. Since both vessels are generally cylindrical, their radial dimension o1' height and width are indicated by G for vessel 2l and by H for vessel 22. The axis XX is the longitudinal extending axis of the vessels 2l, 22. Axes YY and ZZ are common longitudinal extending axes for the members 38, 39 and members 40, di, respectively. Dimensions R, S, locate members 38, 39 and members 40, 421 with respect to the central axis XX of inner vessel 22. Dimension L is the length of the hollow members 38, 39, while M is the length of hollow members 40, 4I contained in the hollow members 38, 39 to the point where the members 40, 41 are in direct heat fiow contact with hollow members 38, 39. Spacing dimension between the inner vessel 2l and outer vessel 22 are indicated by K and J. Dimensions T, W are end spacings. Hollow members 38, 39 are generally circular and have diameters D, E. The dimensions O, N, G, and H will vary widely depending on container capacity and container design. The length O will be generally greater than diameter G; similarly with N and H. Vessel 2l, 22 must be chosen with satisfactory values of O, N, G, and H to provide the desired spacings J, K, T, and W. The members 40, 41 should have high values of the length M to provide a long heat path. Generally, M should be greater than one-half the length N of the inner vessel 22. Members 38, 39 should have diameters D, E, large enough to prevent contact of these members with members 40, 41 over the length M. The locations R, S, of members 40, 41 from the center of vessel 22 may be varied. Dimensions R and S may be up to one-half of dimension H. Effect of increase in dimension is to generate ability to gravity empty the tank and reduce the total length of tube required, when the tank is employed in a horizontal attitude. R should equal S in dimension to best distribute the load. Generally the value of S should be large enough to position the fluid entrance 52 of line 41 close to the bottom of vessel 22. Similarly, fiuid entrance 53 of line 40 should be at the top of vessel 22. The generally uniform annular space portion of the intervening chamber surrounding vessel 22 having a length about equal to N and a thickness equal to l or K is filled with multiple layer insulation 26. Since the annular space is generally uniform J and K will have the same value. This Obstruction free annular space is an important part of the inven tion, as it allows maximum effective utilization of multiple layer insulation and allows the multiple layer insulation to be applied readily. Therefore, the thickness of this annular portion can be reduced. It is preferred that a uniform annular space be used and that this space be filled with an insulation material, as of the powder insulation or preferably of the multiple layer insulation type. The thickness of the multiple layer insulation 26, or of the powder insulation, if used, in the uniform annular space is a function of design requirements, that is, insulating characteristics, envelope dimensions, capacity of inner vessel, etc.

Multiple layer insulation, laminated insulation, laminar insulation, and composite insulation are some of the terms used to identify a specific type of insulation that is advantageously utilized in the containers of this invention. This type of insulation is useful in liquefied gas containers for reducing heat transmission by conduction, convection, and radiation, and consists generally of a series of heat transfer barriers or heat transfer shields. These heat transfer barriers are interposed between the inner and outer vessels of double-walled containers. In the containers of this invention the space between the inner and other vessels is evacuated or vacuum techniques are utilized. The heat barriers of multiple insulation materials are composed of radiation shields or radiation barriers. Multiples of these radiation shields are used. For example, a series or large number of these radiation shields would be placed between the inner and outer vessel of the liquefied gas containers. Generally, the radiation shields are fabricated or utilized in a manner whereby heat conductive paths of the radiation shield material are short; also the shields are spaced or separated to prevent direct heat transfer by conduction between adjacent radiation shields. For example, in many cases the radiation shield is a metal, and a material that is a thermal insulator or has a low thermal` conductivity is used to maintain the spacing of the shields. Generally, winding or wrapping techniques are used to apply the multiple insulation to vessels. For example, fiat sheets may be wrapped around the vessel in a continuous spiral. The winding techniques yield a series of alternating reflective barriers or layers with nonconducting spacer materials. Applying multiple insulation to irregular surfaces, or nonuniform space portions, or spaces containing support systems or fiuid lines, presents many problems and difficulties. As indicated, the uniform annular space-free of obstructions-used in the containers of this invention allows multiple insulation techniques to be used to advantage; wrapping and winding techniques are simply and efiiciently utilized; and complex fabrication procedures are not required to provide multiple layer insulation in this annular space.

FIGURE also illustrates a modification of the axial support system. In this case members 38, 39 extend the length of vessel 22 and are joined to end wall 24. The joint member 42 of FIGURE 1 is not used. The ends of members 40, 41 extend through members 38, 39 and are joined to members 38, 39. Joint members 54, 55 are joined to side wall 24 and members 40, 41. These joint members 54, 55 support lines 40, 41 and prevent excessive bending stresses on the bend end portions of linesI 40, 41.

The improved combination support system-fluid fiow system utilizes members 38, 39 and members 40, 41. Members 40, 41 provide fluid communication from the interior of the inner vessel 22 to points outside of the outer vessel 21. The positioning of members 40, 41 with the hollow portions of members 38, 39 provide fiow lines having long heat leak paths or long heat fiow paths. Generally, readily available materials of construction are advantageously used in the fabrication of the containers. For example, the inner vessel 22 and the outer vessel 3 may be made by welding end portions 23, 24 to lengths of readily available large diameter pipes. In other uses, the shell material will be rolled and welded. Hollow members may be circular, rectangular, or oval crosssectional pipe or tubing.

The rst hollow members 38, 39 are joined, as by welding, to the entrance end 23 of the vessel 22. There is generally no major advantage in having members 38, 39 extend beyond the entrance end 23 into the intervening chamber portion. In most cases the diameters D and E of members 38, 39 will be substantially the same; however, because of fluid flow requirements the diameter of member 40 will usually be equal to or larger than the diameter of member 41. (The volume of liquefied gas flowing into the tank is substantially less than the volume of gas flowing out, during filling, due to expansion in change of state.) The length L of members 38, 39 may be less than the length N of the inner vessel; however, a more rigid support structure is obtained by extending one of the members or both of the members 38, 39 to the opposite end 24 as illustrated in FIGURES 3, 5. The members 33, 39 may be spaced a short distance from the side walls 25. One or more joint members 42 may be used to join the members 38, 39 to the side wall 25. Multiple joint members are illustrated in FIGURE 3. The members 38, 39 may be in direct contact with the side walls 25 and joined by welding along their entire length L to side walls 25.

In general, the containers of this invention are used to provide a modified gravity feed, with the aid of a pressurizing coil, of a liquefied gas, as liquid nitrogen, to an area or compartment containing foodstuffs or container of food. In one application the containers feed a pressurizing coil which in turn builds pressure in the vapor space which drives the liquid into the container to be cooled. The pressurizing coil is fed by gravity. The containers of this invention can also be effective when used for cryogenic trailers, railroad cars, tank mounted trucks, in transporting liquefied gas, or certain stationary containers, primarily those used for liquefied hydrogen.

The containers of this invention can also be used as a receptacle for high temperature fluids, without departing from the spirit and scope of the invention.

While preferred embodiments of the invention have been described, it is to be understood that changes and modifications and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

We claim:

1. A container of double-walled construction comprising an inner vessel, an outer vessel surrounding and spaced from said inner vessel, said inner and outer vessels being of a generally cylindrical shape and having a common longitudinal axis, an intervening vacuum chamber defined by the inner surface of said outer vessel and outer surface of said inner vessel, said intervening vacuum chamber containing insulation materials, a first hollow member extending from an end of said inner vessel to a point in the interior of said inner vessel, a second hollow member extending from said end of said inner vessel to said interior, said members along substantially their entire length being parallel to said longitudinal axis and substantially spaced one on each side of said longitudinal axis so as to be each adjacent to an opposite side of the interior of said inner vessel, said first member and said second member joined to said inner vessel, the interiors of said first member and said' second member communicating with said intervening vacuum chamber, a rst fluid flow line parallel to the longitudinal axis throughout substantially its entire length and extending through said outer vessel and said intervening Vacuum chamber and said interior of said rst member and into the interior of said inner vessel, a second uid flow line parallel to the longitudinal axis throughout substantially its entire length and extending through said outer vessel and said intervening vacuum chamber and said interior of said second member and into the interior of said inner vessel to a point within the inner vessel at the end of the inner vessel opposite to said first-mentioned end, said first line and said second line joined to said outer vessel and joined to said member associated with each said line at a point substantially removed from said point of joining to said outer vessel whereby a substantial heat How path is provided, said rst line and said second line being each separated and spaced from said associated member throughout substantially their entire length, said lines providing fluid communication from the interior of said inner vessel to points outside said outer Vessel, said members and said lines providing an axial support system for maintaining said spacing of said inner and said outer Vessels, and means comprised of thin rods each composed of a material with substantially low heat conductivity characteristics attached to said outer surface of said inner vessel and a side wall of said inner surface of said outer vessel, said means providing radial support for the inner vessel within the outer vessel.

2. A container according to claim 1 wherein said insulation in said chamber is comprised of multiple layer insulation.

3. A container according to claim 1 wherein said means comprised of thin rods includes a rod attached to the outer surface of said end of said inner vessel and a side wall of said inner surface of said outer vessel and rods attached to the outer surface of the end wall opposite the said end of said inner vessel and a side wall of said inner surface of said outer vessel.

References Cited by the Examiner UNITED STATES PATENTS 1,336,439 4/ 1920 Ostrander 220-9 1,863,958 6/1932 Wulff et al. 220-15 2,998,708 9/1961 Skinner 220-10 3,101,862 8/1963 Matsch 220-14 3,132,762 5/1964 Gabarro et al a- 220-15 FOREIGN PATENTS 801,328 9/ 1958 Great Britain.

THERON E. CONDON, Primary Examiner. 

1. A CONTAINER OF DOUBLE-WALLED CONSTRUCTION COMPRISING AN INNER VESSEL, AN OUTER VESSEL SURROUNDING AND SPACED FROM SAID INNER VESSEL, SAID INNER AND OUTER VESSELS BEING OF A GENERALLY CYLINDRICAL SHAPE AND HAVING A COMMON LONGITUDINAL AXIS, AN INTERVENING VACUUM CHAMBER DEFINED BY THE INNER SURFACE OF SAID OUTER VESSEL AND OUTER SURFACE OF SAID INNER VESSEL, SAID INTERVENING VACUUM CHAMBER CONTAINING INSULATION MATERIALS, A FIRST HOLLOW MEMBER EXTENDING FROM AN END OF SAID INNER VESSEL TO A POINT IN THE INTERIOR OF SAID INNER VESSEL, A SECOND HOLLOW MEMBER EXTENDING FROM SAID END OF SAID INNER VESSEL TO SAID INTERIOR, SAID MEMBERS ALONG SUBSTANTIALLY THEIR ENTIRE LENGTH BEING PARALLEL TO SAID LONGITUDINAL AXIS AND SUBSTANTIALLY SPACED ONE ON EACH SIDE OF SAID LONGITUDINAL AXIS SO AS TO BE EACH ADJACENT TO AN OPPOSITE SIDE OF THE INTERIOR OF SAID INNER VESSEL, SAID FIRST MEMBER AND SAID SECOND MEMBER JOINED TO SAID INNER VESSEL, THE INTERIORS OF SAID FIRST MEMBER AND SAID SECOND MEMBER COMMUNICATING WITH SAID INTERVENING VACUUM CHAMBER, A FIRST FLUID FLOW LINE PARALLEL TO THE LONGITUDINAL AXIS THROUGHOUT SUBSTANTIALLY ITS ENTIRE LENGTH AND EXTENDING THROUGH SAID OUTER VESSEL AND SAID INTERVENING VACUUM CHAMBER AND SAID INTERIOR OF SAID FIRST MEMBER AND INTO THE INTERIOR OF SAID INNER VESSEL, A SECOND FLUID FLOW LINE PARALLEL TO THE LONGITUDINAL AXIS THROUGHOUT SUBSTANTIALLY ITS ENTIRE LENGTH AND EXTENDING THROUGH SAID OUTER VESSEL AND SAID INTERVENING VACUUM CHAMBER AND SAID INTERIOR OF SAID SECOND MEMBER AND INTO THE INTERIOR OF SAID INNER VESSEL TO A POINT WITHIN THE INNER VESSEL AT THE END OF THE INNER VESSEL OPPOSITE TO SAID FIRST-MENTIONED END, SAID FIRST LINE AND SAID SECOND LINE JOINED TO SAID OUTER VESSEL AND JOINED TO SAID MEMBER ASSOCIATED WITH EACH SAID LINE AT A POINT SUBSTANTIALLY REMOVED FROM SAID POINT OF JOINING TO SAID OUTER VESSEL WHEREBY A SUBSTANTIAL HEAT FLOW PATH IS PROVIDED, SAID FIRST LINE AND SAID SECOND LINE BEING EACH SEPARATED AND SPACED FROM SAID ASSOCIATED MEMBER THROUGHOUT SUBSTANTIALLY THEIR ENTIRE LENGTH, SAID LINES PROVIDING FLUID COMMUNICATION FROM THE INTERIOR OF SAID INNER VESSEL TO POINTS OUTSIDE SAID OUTER VESSEL, SAID MEMBERS AND SAID LINES PROVIDING AN AXIAL SUPPORT SYSTEM FOR MAINTAINING SAID SPACING OF SAID INNER AND SAID OUTER VESSELS, AND MEANS COMPRISED OF THIN RODS EACH COMPOSED OF A MATERIAL WITH SUBSTANTIALLY LOW HEAT CONDUCTIVITY CHARACTERISTICS ATTACHED TO SAID OUTER SURFACE OF SAID INNER VESSEL AND A SIDE WALL OF SAID INNER SURFACE OF SAID OUTER VESSEL, SAID MEANS PROVIDING RADIAL SUPPORT FOR THE INNER VESSEL WITHIN THE OUTER VESSEL. 